Ecological and evolutionary constraints of plant tolerance to herbivory

一些植物可以耐受草食和组织损伤而不降低适应性（或产量），但我们对耐受性性状的进化和生态知之甚少，甚至对植物补偿能力的机制也知之甚少。此外，我们仍然缺乏对植物防御食草动物的两个组成部分-抗性（避免被吃掉）和耐受性（忍受被吃掉）-在植物生长和繁殖的生态和进化关系中是否存在差异的基本理解。尽管事实上，植物种群中耐受性反应的表达和固定可能会产生巨大的生态后果，例如，通过降低生物防治剂对入侵杂草的有效性，或支持作物中更多样化的昆虫群落。事实上，理论表明，食草性对食草昆虫及其天敌种群动态的影响可能与植物抗性有着根本的不同，例如避免了植物-昆虫抗性进化中典型的进化军备竞赛。对植物耐受性性状及其影响的深入了解，不仅可以解决植物防御变异和植物-昆虫相互作用特异性的一些突出的生态和进化问题，而且还可以为植物改良和保护计划提供一个可操作的目标。

Some plants can tolerate herbivory and tissue damage without reductions in fitness (or yield), yet we know very little about the evolution and ecology of tolerance traits, or even the mechanisms involved in plant compensatory ability. Moreover, we still lack a basic understanding of whether the two components of plant defense against herbivores – resistance (avoiding being eaten) and tolerance (enduring being eaten) – differ in their ecological and evolutionary relationships to plant growth and reproduction. This is despite the fact that the expression and fixation of tolerance responses within plant populations may have immense ecological consequences, e.g. through decreasing the effectiveness of biocontrol agents for invasive weeds, or supporting a more diverse insect community in crops. Indeed, theory suggests that tolerance of herbivory may fundamentally differ from plant resistance in its effects on the population dynamics of insect herbivores and their natural enemies, e.g by avoiding the evolutionary arms race typical in plant-insect resistance evolution. A greater understanding of plant tolerance traits and impact could not only resolve some of the outstanding ecological and evolutionary questions around variation in plant defense and specificity in plant-insect interactions, but also produce an actionable target for plant improvement and protection programs.